An A123 employee works on a bus battery pack. Photo courtesy of A123 Systems.

Battery maker A123 Systems filed for bankruptcy Tuesday, saying that the Milwaukee, Wisconsin-based Johnson Controls would be taking over its automotive operations in a deal valued at $125 million. This past August, A123 had arranged for Chinese auto parts company Wanxiang Group to invest $450 million, but that deal fell apart amid what A123 CEO David Vieau called “unanticipated and significant challenges.” (See full National Geographic News story: “A123 Bankruptcy Underscores Hurdles for U.S. Clean Tech“)

The Wanxiang deal may not be dead, though: BloombergBusinessweek reported Wednesday that Wanxiang is still interested in acquiring A123. Wanxiang executive Ni Pin offered this colorful quote: “Bankruptcy court is like a filter that lets a dirty big boy covered with mud go through it and turn himself into a clean boy. Even though the boy may become smaller, he doesn’t have the obligations he used to have.”

Here’s a look at A123 Systems’ situation by the numbers:

$6 million: Grant money awarded to A123 under the George W. Bush administration’s Department of Energy in 2007.

$249.1 million: Grant money awarded in 2008 by the Obama administration’s DOE to help A123 set up battery manufacturing in Michigan.

$125 million: Level of support provided to A123 from the state of Michigan through tax credits and grants.

$132 million: Amount that A123 has spent from the $249.1 million Energy Department grant awarded in 2009.

$1: Amount that A123 was required to spend from its own funds for every dollar received from the government.

$380 million: Amount that A123 raised in its 2009 initial public offering.